R6 Mark II overwrites min. shutter speed

[5omeone]

Dear DPR community,

I use an R6II and recently took pictures of people in slightly darker environments without flash and with the 50 1.8 STM. I used aperture priority mode (1.8 throughout) and shot with an automatic ISO between 100 and 6400. To avoid severe motion blur, I set the “minimum shutter speed” to 1/250 in the ISO menu (please see here example picture).

Now, in low light conditions, the camera reaches its limits with this setup and sets the ISO to 6400. The shutter speed should now be no longer than 1/250. I would expect the camera to stick to these values and produce a darker image. Instead, the camera “overwrites” the minimum shutter speed and sometimes goes up to 1/30.

I don’t understand how this can be, as I set clear limits for the camera. Am I overlooking a function? Or is this intentional behavior with the R6II?

Many thanks and best regards!

 

[5omeone]

It's the same functionality exhibited on most, if not all, cameras.

If you want the functionality as you state use Manual, set an aperture, set a speed, and set IS0 to auto. Under the situation, as you describe, you will get the desired under exposure.

Yes, you're absolutely right. Well, we're actually beginners and hesitate to take photos manually. ;-)

But honestly, if I set limits for the system, I expect the camera to stick to them. With Auto ISO and the corresponding limits, the maximum value is not simply exceeded because the camera interprets it as too low (people would be outraged if that were the case). And I set both in the same menu!

By the way, the help dialog for this function does not mention the possibility of the shutter speed falling below the minimum.

For us, this is a clear failure.

If the camera operated as you wanted it to, you would have ended up with horribly underexposed images.

It depends, sometimes underexposure is more welcome than motion blurr... ;-) But I got it that "manual" is the way to go.

 

[5omeone]

Safety shift is another, different, function, it isn't part of the ISO related set a minimum shutter speed dialog. Safety shift will alter aperture, SS or ISO in its function.

Perhaps I misunderstood the OP, but the Tv/Av: Shutter speed/Aperture option as described on page 839 seems to describe what happened.

The OP stated that when the selected ISO range ran out of range (couldn't obtain a correct exposure as it reached the set maximum of ISO 6400), the camera adjusted the shutter speed to a value less than the selected Min. shutter speed value.

From page 839 of R8 manual - "Safety shift overrides and changes to [ISO Speed Range] or [Min. shutter speed] from default settings if standard exposure cannot be obtained."

Manual - setting SS and Aperture allowing ISO to be flexible is the way to go. Fixing ISO as well as aperture and SS will fix the exposure.

Safety Shift is used to move a manually set value when the metering system requires it to.

For instance use Av, set a large aperture, say 1.8, and point at a bright scene. Depending on the other auto set values (SS/ISO) the 1.8 will probably be too large to expose correctly. With safety Shift disabled the image will be taken at the manually set 1.8 and the image will be too bright.

With safety Shift enabled, using TV/AV the camera will change your manually set aperture to a smaller value and the image will be taken.

Same but reversed when imaging a dark scene.

It is different functionality to that which the OP aspires to.

Thanks for all the clarification. I'll try to go for manual in future. To be honest, I find these manifold setting options irritating, especially since they are often spread across several menu sections. Even if they make sense in their isolated function, I seriously believe that they have been overcomplicated here.

 

[JohnSil]

It's the same functionality exhibited on most, if not all, cameras.

If you want the functionality as you state use Manual, set an aperture, set a speed, and set IS0 to auto. Under the situation, as you describe, you will get the desired under exposure.

Yes, you're absolutely right. Well, we're actually beginners and hesitate to take photos manually. ;-)

But honestly, if I set limits for the system, I expect the camera to stick to them. With Auto ISO and the corresponding limits, the maximum value is not simply exceeded because the camera interprets it as too low (people would be outraged if that were the case). And I set both in the same menu!

By the way, the help dialog for this function does not mention the possibility of the shutter speed falling below the minimum.

For us, this is a clear failure.

If the camera operated as you wanted it to, you would have ended up with horribly underexposed images.

It depends, sometimes underexposure is more welcome than motion blurr... ;-) But I got it that "manual" is the way to go.

Sometimes manual is the way to go, especially if you have time to set up exposure, such as in most landscapes and especially if you have time to chimp. But if you were shooting in daylight with the sun out and you were shooting an event where you might be shooting in all directions, then each shot exposure will vary depending on the location of the sun or in the case of mottled light among trees. I'm not so sure I ever read WHAT you were shooting?

John

 

[Alastair Norcross]

The main problem, as I see it, is that you are setting your maximum ISO much too low. The R6II can easily handle much higher ISO settings than 6400. I have my ISO range going all the way up to 102400, and the max for auto ISO as 51200. If you are willing to have underexposed shots at 1/250, you can always bring the exposure down in post, which would give you the same noise levels as if you had shot at 6400 with 3 stops underexposure. Another reason to avoid underexposure in camera is that, if you have the viewfinder set for exposure simulation, AF would suffer from a dark view. Unlike with a DSLR, the brightness of the viewfinder affects AF performance. If you wanted a dark exposure for the higher shutter speed, and were planning on raising the exposure in post, you would get exactly the same effect by setting a higher ISO in camera (and maybe slightly better). The main thing to remember is that modern RAW processing software, like DXO or Lightroom's advanced noise reduction, will work wonders. A few years back, with DSLR's and much more basic noise reduction, a maximum ISO of 6400 would have made sense. It simply doesn't anymore. I have absolutely no hesitation in using ISO 51200 on my R6II. One of the posters on this forum regularly shoots at ISO 204800 on his R6II. As I said, if you were prepared to accept a 3 stops underexposed image to get a 1/250 shutter speed, there's just no reason not to allow the camera to shoot at 51200 (or higher). That way, you can always get the same result by lowering the exposure in post (but you don't need to), or you can use modern NR software and be amazed at how good the results will be.

 

[Pierre Lagarde]

... As far as I understand this is the way the OP has the camera set. ...

No, he sets "Minimum shutter speed" in "ISO speed Settings" (SHOOT2), not "Lowest speed" in "Set shutter speed range" (C.Fn2) settings.

These are two different settings, and what I describe works as he's expecting (at least on R5).

+ "Safety Shift" (C.Fn1) also needs to be OFF for this to work.

Read the excerpt of the manual in the link I added.

Yes, thanks for info.

It seems to be designed for something else (Manual and changing lenses/zooming) but, as you say, it does work in this scenario.

Yes. Looks like "Shutter speed range" is more considered as a kind of manual setting by Canon.

Still I - as the OP - consider the behaviour is kind of strange/cumbersome...

It should logically be enough to set minimum shutter speed + safety shift OFF to allow to lock the speed floor... but as there's still a way to force it, in the end, I guess Canon has kind of addressed this need .

Pierre is right, it's exactly the setting I chose. I've done some more research on it now, but I don't fully understand how the various functions work yet, although I do at least know how to deal with them.

I also find it confusing when functions that affect image capturing are spread across several menu sections - what's the point of that? The button assignment is custom, that's clear. But why is setting shutter speed limits a custom function? How is that different from ISO? Did someone mess up there?

Agreed. I guess Canon consider it's a different level of control.

Anyway, thanks... if the solution I gave works for you, can you turn question into "answered" on this post ? => https://www.dpreview.com/forums/post/68486778

This way it will prevent some more misleading posts

 

[JohnSil]

The main problem, as I see it, is that you are setting your maximum ISO much too low.

I have said many times when this subject comes up, "WHY put a limit on the ISO"? Sure as it goes higher and higher there is more and more noise. There's a reason the ISO is going up, there's a lack of light. I'm not talking about landscapes set up on a tripod. I'm talking about images that have movement such as sports. Once one reaches the max ISO, then what? The camera will open the aperture to max, then what? The speed starts to come down until all you have is a blurry mess!

A noisy pic is way better than a blurry mess!!! At least I got the shot!!!

John

 

[Alastair Norcross]

The main problem, as I see it, is that you are setting your maximum ISO much too low.

I have said many times when this subject comes up, "WHY put a limit on the ISO"? Sure as it goes higher and higher there is more and more noise. There's a reason the ISO is going up, there's a lack of light. I'm not talking about landscapes set up on a tripod. I'm talking about images that have movement such as sports. Once one reaches the max ISO, then what? The camera will open the aperture to max, then what? The speed starts to come down until all you have is a blurry mess!

A noisy pic is way better than a blurry mess!!! At least I got the shot!!!

John

I agree for the most part, but there may be borderline cases where a tiny bit more blur from motion is preferable to the extra noise. The difference between the shot at 1/200 and at 1/250 might be less destructive than the difference between using 80,000 ISO and 102,400 ISO. It's at least possible. With slower shutter speeds, especially of people shots, you can sometimes get good results by taking a burst of several shots, and picking the one with the least subject movement. I try to keep my people shots at 1/250 or faster, but I have taken shots as low as 1/60, or even 1/30, and gotten some decent results. It's more a matter of luck at those speeds, to catch someone in a moment of actual stillness.

 

[Pierre Lagarde]

...

Thank you